Certain types of circuit-interrupting devices, such as fuses, discharge hot arc products and gases during fault isolation. The exhaust gases are not typically discharged from the device directly into the atmosphere, but they are instead guided through an exhaust control device. The exhaust control device may include heat absorbing and arc suppressing material to reduce the temperature and energy of the discharged arc products and may further provide sound suppression.
Exhaust control devices are capable of both reducing the sound level and the gas discharge without significantly interfering with the intended circuit-interrupting function of the fuse or device. Further, these devices, unlike non-vented devices, do not create unsuitably high back pressures to the circuit-interrupting device which might cause undesirable effects, including higher pressures and operating temperatures, longer arcing time, and higher operating energies that must be dissipated. It is also desirable that the exhaust control device be as small and light-weight as possible, while retaining efficiency of operation and being capable of functioning repeatedly without loss of effectiveness. An exemplary exhaust control device is disclosed and described in commonly assigned U.S. Pat. No. 4,788,519, the disclosure of which is hereby expressly incorporated herein by reference.
While designed for repeated use, an exhaust control device has a finite useful life after which it must be replaced. Use of an exhaust control device after it has reached its useful life may result in the dangerous discharge of hot arc products and gases. However, it can be difficult to know whether the device has reached the end of its useful life. A manufacturer may specify criteria that define a condition or conditions of one or more components of the device indicative of the end of its useful life. For example, should a baffle of the device be ruptured or eroded beyond a specified condition the exhaust control device is deemed to be beyond its useful life. However, it may be difficult to determine the condition of the one or more component, and moreover, determining the condition requires periodic inspection by trained personnel.